This application claims the priority benefit of Taiwan application serial no. 89127829, filed Dec. 26, 2000.
1. Field of Invention
The present invention relates to a method of manufacturing liquid crystal display (LCD). More particularly, the present invention relates to an in-line operation system and flow plan for manufacturing liquid crystal display.
2. Description of Related Art
Liquid crystal display (LCD) is incorporated into a variety of consumer electronic and computer products such as portable televisions, mobile telephones, camcorders, notebook computers, desktop monitors and projection televisions. Major advantages of a LCD include its high-quality picture, light and streamline body, low voltage driver and low power consumption. Hence, LCD is gradually replacing cathode ray tube (CRT) as the preferred means of display.
The main body of a liquid crystal display is a liquid crystal unit consisting of two transparent panels and a layer of liquid crystal between the panels. At present, thin film transistor (TFT) is the dominant type of liquid crystal display. In general, the manufacturing of a TFT type LCD can be grouped into three stages: the production of the thin film transistor (TFT) array, the assembly of the liquid crystal cell and the fabrication of the liquid crystal module.
In the production of a TFT LCD, the production of a TFT array includes producing a thin film transistor panel. The assembly of the liquid crystal unit includes joining two thin film transistor panels together and injecting liquid crystal into the space between the panels to form a liquid crystal unit. The fabrication of the liquid crystal module includes attaching a polarizer to the liquid crystal display panel, connecting the circuit inside the liquid crystal display panel with a driver IC and installing of reflectors or back lights. Finally, burn-in testing is conducted after the module is formed.
At present, off-line operation is employed in the production of a liquid crystal display from liquid crystal cell assembly to liquid crystal module assembly. FIG. 1 is a flow chart showing the steps in a conventional off-line operation method for fabricating liquid crystal display from the assembly of liquid crystal cell to the assembly of liquid crystal module. As shown in step 100 of FIG. 1, the semi-finished product after liquid crystal is sealed in the space between liquid crystal panels is placed in a first stocking region. In step 102, the semi-finished product is pulled by a loader from the first stocking region. In step 104, the completely assembled liquid crystal cell is shunt-separated, beveled and corner-cut. In step 106, cullets that form due to the cutting, the beveling and the corner smoothing operations are removed. In step 108, the semi-finished is further cleaned by brush washing. In step 110, the semi-finished product is placed in a second stocking region using an unloader.
As shown in FIG. 1, the semi-finished product is pulled from the second stocking region in step 112 to perform a visual inspection after completing the steps for producing a liquid crystal cell. In step 114, the semi-finished product is placed in a third stocking region ready so that the semi-finished product can be pulled from the third stocking region when liquid crystal module needs to be fabricated. Hence, between the assembly of the liquid crystal cell and the assembly of the liquid crystal module, the semi-finished product is unloaded from the production line and stored in a stocking buffer, typical for an off-line operation.
To fabricate the liquid crystal module as shown in FIG. 1, the inspected liquid crystal display cell is pulled out from the third stocking region by a loader in step 116. In step 118, the liquid crystal cell is brush-washed to clean all the exposed surfaces. In step 120, a polarizer is affixed to the surface of the liquid crystal cell. In step 122, the semi-finished product is unloaded from the production line to a fourth stocking region ready for subsequent use.
However, because of the selection of off-line operation between the assembly of the liquid crystal cell and the assembly of liquid crystal module, a production line with a length of at least 50 m to 60 m is required.
Accordingly, one object of the present invention is to provide an in-line operation installation and flow plan that uses a linked stocking region to directly connect the assembly line for producing liquid crystal cell and the assembly line for producing liquid crystal module. By automating the transfer of semi-finished product between the two assembly lines, the number of stocking regions, processing machines and operators needed in the production line is reduced. By carrying out a single brush washing instead of a cullet cleaning and a brush washing operation, length of the production line can be reduced without affecting product yield. In addition, by linking an inspection cell with a connected stocking region, the semi-finished product can be inspected on line rather than off line in a full visual inspection. Without off line inspection, production time and area needed for production are reduced. Hence, product cycle is reduced, product yield is increased and production line administration is simplified.
This invention also provides an in-line operation for manufacturing liquid crystal displays. First, a liquid crystal cell is pulled out from a first stocking region and placed inside a processing station by a loader. The liquid crystal cell is shunt, beveled and corner-cut by a shunt and bevel unit inside the processing station. The liquid crystal cell is next transferred directly to a brush-washing unit for cleaning. After cleaning, the semi-finished product is directly transferred from a linked stocking region to an affixing unit for attaching a polarizer onto the liquid crystal cell. The semi-finished product is transferred to a second stocking region by an unloader. Sample inspection can be carried out when the semi-finished product is still within the linked stocking region. The inspected semi-finished product passing through the linked stocking region can be brush-washed a second time before transferring to the affixing unit for attaching a polarizer. The second brush-washing unit is inserted between the linked stocking region and the affixing unit.
In addition, this invention provides an in-line operation system that includes a stocking region for holding liquid crystal cell, a shunt and bevel unit, a brush-washing unit, a linked stocking region, an affixing unit, an inspection unit and a second stocking region for holding semi-finished liquid crystal module. The brush-washing unit, the inspection unit, the shunt and bevel unit, the linked stocking region are joined together. Furthermore, the shunt and bevel unit may include a directly attached loader while the affixing unit may include a directly attached unloader. A second brush-washing unit that joins up directly with the affixing unit and the linked stocking region may be added.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.